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When to Plant Onion in Garvin County, OK

Onions are a fundamental kitchen staple available in yellow, white, and red varieties. Choose long-day, short-day, or intermediate types based on your latitude.

Garvin County, Oklahoma is in USDA Zone 7b. The average last spring frost is April 4 and the first fall frost is November 3, giving you a growing season of approximately 213 days.

At an elevation of 515 feet, Garvin County receives approximately 31.4 inches of rainfall annually with predominantly loam soil. Summer highs average 93ยฐF, providing good warmth for Onion during the growing season.

Garvin County, OK (Zone 7b) Long season
213 days
Last Spring Frost April 4
213 growing days
First Fall Frost November 3

Garvin County Soil Profile

Soil Type

Loam

Soil pH

6.3-7.2

Drainage

Well Drained

Monthly Watering Guide for Onion

Onion needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Onion Needs Rainfall You Supplement Action
Jan โ€” 0.7" 0" โ„๏ธ Dormant
Feb โ€” 1.2" 0" โ„๏ธ Dormant
Mar โ€” 2.2" 0" โ„๏ธ Dormant
Apr 4.3" 3.2" 1.1" ๐Ÿ’ง Light watering
May 4.3" 4.1" 0.2" ๐Ÿ’ง Light watering
Jun 4.3" 5" 0" โœ… Rainfall sufficient
Jul 4.3" 4.1" 0.2" ๐Ÿ’ง Light watering
Aug 4.3" 4.1" 0.2" ๐Ÿ’ง Light watering
Sep 4.3" 2.9" 1.4" ๐Ÿ’ง Light watering
Oct 4.3" 2.1" 2.2" ๐Ÿšฟ Regular watering
Nov 4.3" 1.1" 3.2" ๐Ÿšฟ Regular watering
Dec โ€” 0.8" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Nov in Garvin County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Onion Planting Timeline โ€” Garvin County, OK

Onion Planting Calendar

Activity When Date Range
Start Indoors February 28 Feb 28 โ€“ Mar 14
Transplant Outdoors April 4 Apr 4 โ€“ Apr 18
Direct Sow March 21 Mar 21 โ€“ Apr 11
Harvest July 4 Jul 4 โ€“ Aug 22
Fall Sowing August 25 Aug 25 โ€“ Sep 8

Plant 1" deep ยท 6" apart ยท Rows 12" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February Start Indoors
March Start Indoors Direct Sow
April Transplant Outdoors Direct Sow
May โ€”
June โ€”
July Harvest
August Fall Sowing Harvest
September Fall Sowing
October โ€”
November โ€”
December โ€”

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

Moderate โ€” regular watering

๐Ÿ“… Days to Maturity

90โ€“120 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: N/A

๐Ÿ—บ๏ธ USDA Zone

Zone 7b

๐Ÿ“† Growing Season

213 days in Garvin County

Growing Tips for Garvin County

Start seeds indoors 8-10 weeks before transplanting. Match day-length type to your latitude. Stop watering when tops begin to fall over and cure bulbs for 2-3 weeks before storage.

Companion Planting

Good Companions

Avoid Planting Near

  • Peas
  • Green Beans
  • Asparagus

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Onion in Garvin County, OK?

Garvin County is in Zone 7b with an average last frost of April 4. Plan your Onion planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Garvin County, OK?

Garvin County, Oklahoma is in USDA Hardiness Zone 7b. The average last spring frost is April 4 and first fall frost is November 3.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Garvin County gardeners in Zone 7b organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Garvin County, OK. Local conditions may vary. Last updated: April 2026.